If the foundation is weak, first focus on textbooks and do more after-school exercises. Those questions are carefully selected, but they are often ignored or considered useless by many students ... Then there are a lot of questions ... But don't do a whole set of questions ... But you should make a breakthrough in the topic, think while doing it, pay more attention to the use of conditions, and see the questions clearly ... Of course, the sea is the best way, from easy to difficult ... I am very optimistic about you. ...